<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        html, body {
            margin: 0;
            height: 100%;
        }

        canvas {
            display: block;
        }

    </style>
</head>
<body onload="draw();">

</body>
<script src="http://www.yanhuangxueyuan.com/versions/threejsR92/build/three.js"></script>
<script src="js/controls/OrbitControls.js"></script>
<script src="js/libs/stats.min.js"></script>
<script src="js/libs/dat.gui.min.js"></script>
<script>
    var renderer;

    function initRender() {
        renderer = new THREE.WebGLRenderer({antialias: true});
        renderer.setSize(window.innerWidth, window.innerHeight);
        //告诉渲染器需要阴影效果
        renderer.shadowMap.enabled = true;
        renderer.shadowMap.type = THREE.PCFSoftShadowMap; // 默认的是，没有设置的这个清晰 THREE.PCFShadowMap
        document.body.appendChild(renderer.domElement);
    }

    var camera;

    function initCamera() {
        camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
        camera.position.set(0, 40, 100);
        camera.lookAt(new THREE.Vector3(0, 0, 0));
    }

    var scene;

    function initScene() {
        scene = new THREE.Scene();
    }

    var ambientLight, directionalLight;

    function initLight() {

        ambientLight = new THREE.AmbientLight("#111111");
        scene.add(ambientLight);

        directionalLight = new THREE.DirectionalLight("#ffffff");
        directionalLight.position.set(-40, 60, -10);

        directionalLight.shadow.camera.near = 20; //产生阴影的最近距离
        directionalLight.shadow.camera.far = 200; //产生阴影的最远距离
        directionalLight.shadow.camera.left = -50; //产生阴影距离位置的最左边位置
        directionalLight.shadow.camera.right = 50; //最右边
        directionalLight.shadow.camera.top = 50; //最上边
        directionalLight.shadow.camera.bottom = -50; //最下面

        //这两个值决定使用多少像素生成阴影 默认512
        directionalLight.shadow.mapSize.height = 1024;
        directionalLight.shadow.mapSize.width = 1024;

        //告诉平行光需要开启阴影投射
        directionalLight.castShadow = true;

        scene.add(directionalLight);
    }

    var cube, plane, meshMaterial;

    function initModel() {

        //辅助工具
        var helper = new THREE.AxisHelper(10);
        scene.add(helper);

        //球体
        var sphereGeometry = new THREE.SphereGeometry(10, 30, 30);
        meshMaterial = new THREE.MeshBasicMaterial({color: 0xaaafff});
        var sphere = new THREE.Mesh(sphereGeometry, meshMaterial);
        sphere.position.set(-20, 20, 0);

        sphere.castShadow = true;

        scene.add(sphere);

        //立方体
        var cubeGeometry = new THREE.CubeGeometry(10, 10, 10);

        var cubeMaterial = new THREE.MeshLambertMaterial({color: 0x00ffff});

        cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
        cube.position.x = 30;
        cube.position.y = 5;
        cube.position.z = -5;

        //告诉立方体需要投射阴影
        cube.castShadow = true;

        scene.add(cube);

        //底部平面
        var planeGeometry = new THREE.PlaneGeometry(5000, 5000, 20, 20);
        var planeMaterial = new THREE.MeshLambertMaterial({color: 0xaaaaaa});

        plane = new THREE.Mesh(planeGeometry, planeMaterial);
        plane.rotation.x = -0.5 * Math.PI;
        plane.position.y = -0;

        //告诉底部平面需要接收阴影
        plane.receiveShadow = true;

        scene.add(plane);

    }


    //初始化dat.GUI简化试验流程
    var controls;

    function initGui() {
        //声明一个保存需求修改的相关数据的对象
        controls = {
            rotationSpeed: 0.02,
            bouncingSpeed: 0.03,

            opacity: meshMaterial.opacity,
            transparent: meshMaterial.transparent,
            overdraw: meshMaterial.overdraw,
            visible: meshMaterial.visible,
            side: "front",

            color: meshMaterial.color.getStyle(),
            wireframe: meshMaterial.wireframe,
            wireframeLinewidth: meshMaterial.wireframeLinewidth,
            wireFrameLineJoin: meshMaterial.wireframeLinejoin,
        };

        var gui = new dat.GUI();


        var spGui = gui.addFolder("Mesh");
        spGui.add(controls, 'opacity', 0, 1).onChange(function (e) {
            meshMaterial.opacity = e
        });
        spGui.add(controls, 'transparent').onChange(function (e) {
            meshMaterial.transparent = e
        });
        spGui.add(controls, 'wireframe').onChange(function (e) {
            meshMaterial.wireframe = e
        });
        spGui.add(controls, 'wireframeLinewidth', 0, 20).onChange(function (e) {
            meshMaterial.wireframeLinewidth = e
        });
        spGui.add(controls, 'visible').onChange(function (e) {
            meshMaterial.visible = e
        });
        spGui.add(controls, 'side', ["front", "back", "double"]).onChange(function (e) {
            console.log(e);
            switch (e) {
                case "front":
                    meshMaterial.side = THREE.FrontSide;
                    break;
                case "back":
                    meshMaterial.side = THREE.BackSide;
                    break;
                case "double":
                    meshMaterial.side = THREE.DoubleSide
                    break;
            }
            meshMaterial.needsUpdate = true;
            console.log(meshMaterial);
        });
        spGui.addColor(controls, 'color').onChange(function (e) {
            meshMaterial.color.setStyle(e)
        });

        spGui.open();

    }

    //初始化性能插件
    var stats;

    function initStats() {
        stats = new Stats();
        document.body.appendChild(stats.dom);
    }

    //用户交互插件 鼠标左键按住旋转，右键按住平移，滚轮缩放
    var controls;

    function initControls() {

        controls = new THREE.OrbitControls(camera, renderer.domElement);

        // 如果使用animate方法时，将此函数删除
        //controls.addEventListener( 'change', render );
        // 使动画循环使用时阻尼或自转 意思是否有惯性
        controls.enableDamping = true;
        //动态阻尼系数 就是鼠标拖拽旋转灵敏度
        //controls.dampingFactor = 0.25;
        //是否可以缩放
        controls.enableZoom = true;
        //是否自动旋转
        controls.autoRotate = false;
        //设置相机距离原点的最远距离
        controls.minDistance = 50;
        //设置相机距离原点的最远距离
        controls.maxDistance = 200;
        //是否开启右键拖拽
        controls.enablePan = true;
    }

    function render() {
        renderer.render(scene, camera);
    }

    //窗口变动触发的函数
    function onWindowResize() {

        camera.aspect = window.innerWidth / window.innerHeight;
        camera.updateProjectionMatrix();
        render();
        renderer.setSize(window.innerWidth, window.innerHeight);

    }

    function animate() {
        //更新控制器
        render();

        //更新性能插件
        stats.update();

        controls.update();

        requestAnimationFrame(animate);
    }

    function draw() {
        initRender();
        initScene();
        initCamera();
        initLight();
        initModel();
        initGui();
        initControls();
        initStats();

        animate();
        window.onresize = onWindowResize;
    }
</script>
</html>